1. Field of the Invention
The present invention relates to medical methods and systems. More particularly, the invention relates to a method and system for positioning patients that undergo medical treatment procedures.
2. The Related Art
The accurate placement and positioning of patients is crucial when performing many types of medical treatments. One category of medical treatments in which the proper placement and verification of the position of patients/patient body parts is of particular importance is in the field of radiation therapy.
Radiation therapy involves medical procedures that selectively expose certain areas of a human body, such as cancerous tumors, to high doses of radiation. The intent of the radiation therapy is to irradiate the targeted biological tissue such that the harmful tissue is destroyed. To minimize damage to surrounding body tissues, many conventional treatment methods utilize "dose fractionating" to deliver the radiation dosage in a planned series of treatment sessions that each delivers only a portion of the total planned dosage. Healthy body tissues typically have greater capacity to recover from the damage caused by exposed radiation. Spreading the delivered radiation over many treatment sessions allows the healthy tissue an opportunity to recover from radiation damage, thus reducing the amount of permanent damage to healthy tissues while maintaining enough radiation exposure to destroy tumoral tissue.
The efficacy of the radiation treatment depends in large part upon the ability to irradiate the exact same position on the body at the various radiation sessions. The goal is to place the patient in the same position relative to the radiation source at each and every treatment session. Inaccuracies in positioning the patient could result in errors in radiation dosage and/or treatment locations, leading to unpredictable disease relapse or damage to healthy tissues. Maintaining the linear accelerator/radiation source in a precise and repeatable position does not normally present a problem. The problem arises when attempting to recreate the same body position by the patient at every radiation session. In conventional medical treatment systems, the accurate placement and verification of a repeating treatment location on the human body remains a significant problem in implementing dose fractionating treatment plans.
One approach to controlling patient positioning is to place marks or tattoos at specific locations on the patient's skin. Several laser or light sources from predetermined locations project beams of light at the patient's body. To control the patient positioning, a therapist shifts the position of the patient until the marks are aligned with the lines of light from the lasers or light sources. A significant drawback to this approach is that the accuracy and consistency of the patient positioning is heavily dependent upon the skill level of the therapist in manually positioning the patient. In addition, with heavier patients, it is possible that only the skin of the patient is moved into the proper position without moving the body part to be irradiated into the appropriate position. Moreover, this approach does not provide an efficient way to record and reflect the positioning quality in the patient's records.
Another approach to controlling patient positioning is to utilize an immobilization device to maneuver the patient into a particular position. An immobilization device physically attaches to the human body to keep the patient from moving once proper positioning is achieved. A drawback to using an immobilization device is that such devices to not exist for all body parts. Immobilization devices are generally effective only for positioning the head and neck of a patient. Moreover, in many known immobilization devices, a patient can still move to a significant degree within the confines of the immobilization device. In addition, these devices can be extremely uncomfortable for the patient.
Positioning a patient with video cameras has been applied to stereotactic radiosurgery of the brain where the patient's skull is positioned as a rigid object. However, there are drawbacks to applying known positioning techniques using video cameras to non-rigid portions of the body. For example, such implementations have been incapable of effectively guiding the therapist through the steps to be taken for achieving proper posture and position. Therefore, therapist confusion occurs resulting in a lengthy positioning process.
Thus, there is a need for a system and method to address the above-described problems of the related art. There is a need for a method and system that can accurately and consistently control the position of a patient for medical treatment.